Why should eggs be refrigerated in the US but not in Europe and the best place to store them?
- Eggs in the US need to be refrigerated to slow the growth of any potential salmonella bacteria.
- In some other countries, eggs are less likely to contain salmonella and do not require refrigeration.
- You can always put them in the fridge to extend the shelf life of eggs, but be sure to store them correctly.
Eggs are a staple food in many households, but how you store them depends largely on which country you are in.
For example, if you’re in England you typically won’t refrigerate your eggs while in the US you will.
It is important to store eggs properly because they are one of the leading causes of a foodborne illness called salmonellosis, which affects 1.35 million Americans and more than 91,000 Europeans each year.
While it is perfectly safe to store any egg in the refrigerator, there is a very good reason why eggs do not require this extra step in many countries.
How can eggs be contaminated with salmonella?
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There are two ways that an egg can become infected with salmonella (the bacteria that cause salmonellosis), says Ada Hagan, PhD, a microbiologist with Alliance Psycom & Consulting, LLC:
1. An egg may be laid with salmonella bacteria already within the shell. This happens when a hen is infected with salmonella and then lays an egg.
2. Salmonella can enter the shell after it is stored. This occurs when the egg comes into contact with the stool and bacteria from the stool enter the shell.
For the latter case, bacteria can enter a shell for some reason such as the shell is broken or the cuticle, a protective outer layer, is damaged.
Another approach is if the eggshell develops condensation, which can promote salmonella growth, as the bacteria thrive in warm, moist environments to produce condensation. The more salmonella you have on hand, the more likely it is that something will enter the shell.
“There are many ways to prevent both of these events from occurring at multiple stages in egg farming and processing,” Hagan says.
Egg Processing in America vs. Europe
American eggs that are washed and dried can remove the protective cuticle and are more likely to be contaminated with bacteria if left unrefrigerated. barbaragibbon/Getty Images
There are four essential ways to reduce the risk of salmonella contamination in eggs, Hagan says.
- Shorten the time between egg laying and feeding so that any bacteria in the egg don’t have time to multiply to dangerous amounts.
- Wash and clean the eggs to remove contaminants such as dirt or feces from the outside of the shell.
- Keep eggs dry to avoid condensation and subsequent contamination.
- Avoid temperature fluctuations, which can lead to the formation of condensation.
Egg Processing in America
In America, eggs are washed and dried. However, this process removes the cuticle, a protective coating on the egg. Because of that, American eggs are more prone to infection with salmonella.
Therefore, it is legally required by US food processing regulations that commercial eggs be refrigerated at a constant temperature of 45˚F.
In addition, “eggs are refrigerated to avoid temperature fluctuations and extend shelf life, essentially ignoring the first method,” Hagan says.
egg processing in europe
In Europe and the rest of the world, the standard emphasizes preserving the cuticle and getting the eggs to consumers quickly.
For example, in Europe, eggs are marked “best first” 28 days after being laid, while in the US, commercially processed eggs have a “sale” or expiration date, packaged in cartons. up to 30 days after it is done.
“Countries that don’t refrigerate their eggs have a different way of avoiding contaminated eggs, which reduces time on the table and never requires refrigeration,” Hagen says.
The eggs are packaged near where they are laid, and do not undergo a sanitation process. In addition, some countries such as the UK vaccinate chickens against Salmonella.
note: In the US, some major retailers such as Costco and Walmart require vaccinations for birds they sell as meat but not for egg layers.
While the procedures are different, both are effective.
“No method of food safety protocol is better at protecting against salmonella,” says Brian Chow, a food scientist trained through the FDA’s Foreign Supplier Verification Program and chef at Chow Time.
How long can you keep eggs unrefrigerated
Freshly laid eggs are safe without refrigerating for about two weeks. Julian Forniol/BallouMix/Getty Images
How long you can keep eggs will depend on how they are processed and stored.
“Generally speaking, nest cleaned — unwashed, unrefrigerated — eggs have a shorter shelf life than washed, refrigerated eggs,” Hagan says.
This is because refrigeration slows the growth of bacteria. Turns out, even though salmonella makes it into the shell, eggs have immune defenses that slow the growth of the bacteria, Hagan says.
If you buy refrigerated eggs at the market, like most people in America, you can safely store them in the fridge for up to 35 days (five weeks).
If, however, you buy eggs fresh from the farm — or collect them from your backyard coop — those eggs can be left unrefrigerated at room temperature for 14 to 21 days. But there is no harm in keeping them in the fridge to extend their shelf life a little longer.
note: Refrigerated eggs should be discarded if they’ve been at room temperature for two hours or more, says Chow. This reduces the risk of foodborne illness because it prevents eggs from staying in the “danger zone” (between 40 F and 140 F) for too long.
In the U.S., whether you’re buying commercially produced eggs that need to be refrigerated or farm-fresh at room temperature, there are some cases where you should discard your eggs, Chow says:
- If the shell is cracked or particularly dirty.
- If there is any strange smell.
- If there is any slime or other changes in the appearance of the eggshell.
quick Tip: Unfortunately, there is no reliable way to tell if an egg contains salmonella. “It may be loaded with salmonella, but look, taste, and smell similar to an uninfected egg,” Hagan says.
best place to store your eggs
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When you store eggs, the key is maintaining a consistent temperature. The USDA requires that eggs be stored at a temperature of 45 F or lower, says Chef Corrigan Duffy of Kori Cooks. You should maintain that temperature at home as well.
If you refrigerate your eggs, the best place to store them is obviously your fridge, but some spots are better than others.
“Despite how convenient a refrigerator door may appear, eggs should be kept on the middle shelf of your fridge, preferably on the back side,” says Duffy. This is where the temperature is coldest and most consistent.
If you’re outside the U.S. or you’ve purchased farm-fresh eggs that don’t require refrigeration, keep them on the counter or table at a temperature between about 62-73 F, Chou says. If it gets hotter than your home, opt for a fridge instead.
quick Tip: Just be sure to remove the eggs about an hour before baking with them. Room temperature eggs will blend into more frequent recipes, improving your final product.
Insider Takeaway
Eggs sold commercially in the US undergo a washing and cleaning process that removes contaminants, but also removes the natural defenses that eggs have against bacteria.
Because of this, eggs are refrigerated during processing and must be kept cold to reduce the risk of salmonella contamination.
“Once the eggs are cold, they should remain cold,” Hagan says.
However, farm-fresh eggs and, in European countries and much of the world, can be kept safely at room temperature for up to two weeks, Chou says.
However, there are no disadvantages to keeping eggs cold. “If in doubt, eggs in the fridge do no harm,” Chou says.
